Question:
Given below are two statements :
Statement I : A speech signal of $2 \mathrm{kHz}$ is used to modulate a carrier signal of $1 \mathrm{MHz}$.
The bandwidth requirement for the signal is $4 \mathrm{kHz}$.
Statement II : The side band frequencies are $1002 \mathrm{kHz}$ and $998 \mathrm{kHz}$. In the light of the above statements, choose the correct answer from the options given below :
Correct Option: , 4
Solution:
Side band $=\left(f_{c}-f_{m}\right)$ to $\left(f_{c}+f_{m}\right)=(1000-2) \mathrm{KHz}$ to $(1000+2) \mathrm{KHz}$
$=998 \mathrm{KHz}$ to $1002 \mathrm{kHz}$
Band width $=2 \mathrm{f}_{\mathrm{m}}$
$=2 \times 2 \mathrm{KHz}$
$=4 \mathrm{KHz}$
Both statements are true